Optical fiber or waveguide lens

Abstract

Method of making a lens on an optical fiber or waveguide using a femtosecond laser. The lens may be further smoothed by the application of heat.

What is claimed is:  
     
       1. A method of making a lens on an optical fiber comprising: 
       providing a laser system having a power density of at least 10 15  W/m 2  and a laser pulse duration of one picosecond or less;  
       subjecting the end of an optical fiber to the laser to ablate a portion of the optical fiber such that a lens pre-shape is obtained; and  
       subjecting the ablated portion of the optical fiber to a heat source to smooth the lens surface into a desire shaped.  
     
     
       2. The method of  claim 1 , wherein the heat source is selected from the group consisting of an electrical arc, a CO 2  laser, and a flame. 
     
     
       3. The method of  claim 1  wherein the power density is from about 10 17  to 10 18  W/m 2 . 
     
     
       4. The method of  claim 1  wherein the laser system comprises two lenses with different focal lengths. 
     
     
       5. The method of  claim 1  wherein the laser system comprises an aspheric lens. 
     
     
       6. The method of  claim 1  wherein the lens shape can be controlled by adjusting the cutting angle of the laser. 
     
     
       7. The method of  claim 1 , wherein the lens shape can be controlled by adjusting the intensity and duration of the heat application. 
     
     
       8. The method of  claim 1  wherein the optical fiber is subjected to the laser for more than one pass. 
     
     
       9. The method of  claim 1  wherein the laser operates at a wavelength of about 900 nm or less. 
     
     
       10. A method of making a lens on an optical waveguide comprising: 
       providing a laser system having a power density of at least 10 15  W/m 2  and a laser pulse duration of one picosecond or less;  
       subjecting the end of an optical waveguide to the laser to ablate a portion of the waveguide such that a lens pre-shape is obtained; and  
       subjecting the ablated portion of the waveguide to a heat source to smooth the lens surface into a desired shape.  
     
     
       11. The method of  claim 10 , wherein the heat source is selected from the group consisting of an electrical arc, a CO 2  laser, and a flame. 
     
     
       12. The method of  claim 10  wherein the power density is from about 10 17  to 10 18  W/m 2 . 
     
     
       13. The method of  claim 10  wherein the laser system comprises two lenses with different focal lengths. 
     
     
       14. The method of  claim 10  wherein the laser system comprises an aspheric lens. 
     
     
       15. The method of  claim 10  wherein the lens shape can be controlled by adjusting the cutting angle of the laser. 
     
     
       16. The method of  claim 10 , wherein the lens shape can be controlled by adjusting the intensity and duration of the heat application. 
     
     
       17. The method of  claim 10  wherein the waveguide is subjected to the laser for more than one pass. 
     
     
       18. The method of  claim 10  wherein the laser operates at a wavelength of about 900 nm or less. 
     
     
       19. The method of  claim 10  wherein the optical waveguide is a planar optical circuit.